Causes:
1. One of the earphones has run out of battery, so only one earphone can connect to the phone.
2. Bluetooth earphones are sensitive to electromagnetic waves in your area, which may affect the Bluetooth connection. Sometimes, only one earphone can connect after you open the charging case.
3. The earphone is not touching the charging case well, so it does not get the signal to turn on from the case. It may not connect automatically or only connect to one ear.
Solutions:
1. Please charge both earphones and make sure that both earphones are charged.
2. Try to stay away from microwave ovens, railway stations, and other objects with large electromagnetic interference.
3. Check whether the golden yellow contacts of the earphone or the charging case are dirty. If so, use a soft cloth dipped in a small amount of medical alcohol to wipe the metal contacts of the earphone and the charging case. Be careful not to use water and corrosive liquids to wipe the metal contacts, and do not wipe them too hard to avoid water in the earphones or deformation of the contacts.
4. Please pair the earphone again.
5. If you still cannot connect, please restart your phone and reset your earphones.
If the issue remains unresolved, take your device and proof of purchase to an authorized realme Service Center for assistance.